Thailand will nominate the ancient Thai city of Chiang Saen and the companion Lao city of Suvannakhomkham to the United Nations Educational Scientific and Cultural Organization (UNESCO) for jointly listing of world heritage sites, Thai News Agency reported.

The news agency quoted Thai Culture Minister Teera Slukpetch assaying that the trans-boundary archaeological urban complex of Chiang Saen and Suvannakhomkham, with a history of about 500-600 years, is at the Mekong River gateway, where the recursors of today's Thailand and the Laos absorbed the Chinese and Indian cultures, and developed their own unique cultures long ago.

The ministry also plans to nominate four other historic sites for consideration by UNESCO next year.

The other four heritage sites are the Srivichaya cultural heritage in the south, Lanna culture in the north, the culture of the central region along the Chao Phraya River and distinctive architecture of Prince Narisara Nuvativongse in the Rattanakosin Period.